On May 10, 2018, the Board ratified and confirmed the 2014 Equity Incentive Plan (the “2014 Plan”). The 2014 Plan is a broad-based plan under which 5,550,750 shares of our common stock are authorized for issuance for awards, including stock options, stock appreciation rights, restricted stock, and cash incentive awards to members of our Board, executive officers, employees and independent contractors. As of September 30, 2018, 689,000 shares remained available for issuance as new awards under the 2014 Plan.

Stock options. During the nine months ended September 30, 2018 and 2017, we issued 270,000 and 1,390,000 options to purchase our common stock, respectively, to members of our Board, executive officers, employees and independent contractors.

The fair value of all stock options granted for the nine months ended September 30, 2018 and 2017 was determined to be $169,807 and $652,895, respectively, using the Black-Scholes option pricing model with the following assumptions:

Nine Months Ended September 30, 2018

Nine Months Ended September 30, 2017

Dividend yield

0%

0%

Expected volatility

78%

80 - 87%

Risk free interest rate

2.46% - 2.73%

1.73 - 1.94%

Expected life (years)

5.00

5.00

A summary of stock option activity is as follows:

Common stock options

Weighted-

average

exercise price

Aggregate

intrinsic

value

Weighted-average

remaining contractual

term (years)

Outstanding – December 31, 2017

2,811,250

$

0.54

$

1,849,517

3.65

Issued

270,000

0.98

—

—

Exercised

—

—

—

—

Expired

—

—

—

—

Outstanding – September 30, 2018

3,081,250

$

0.58

$

2,186,179

3.05

Exercisable – September 30, 2018

2,317,916

$

0.52

$

1,775,996

2.78

A summary of unvested stock option activity is as follows:

Common stock

options

Weighted-average

exercise price

Aggregate

intrinsic

value

Weighted-average

remaining contractual

term (years)

Unvested – December 31, 2017

825,557

$

0.63

$

467,379

4.27

Granted

270,000

0.98

—

—

Vested

(332,223

)

0.64

—

—

Forfeited or expired

—

—

—

—

Unvested – September 30, 2018

763,334

$

0.75

$

410,184

3.82

As of September 30, 2018, our unrecognized stock-based compensation expense associated with the stock options issued was $299,788, which will be amortized over a weighted-average of 1.81 years.

Warrants. On August 29, 2016, in connection with the Breakaway Term Loan Agreement, we issued the lenders the Warrants to purchase 1,965,780 shares of our common stock at an initial exercise price of $0.30 per share. On April 24, 2018, we paid $1,333,333 to redeem the Warrants in full upon extinguishment of the Breakaway Term Loan (Note 10).